So Many Analog To Digital Converters

June 11, 2026 by Al Williams 44 Comments

An old algebra teacher used to say, “You have to take what you know and use it to get what you don’t know.” You might say the same thing about converting analog signals into digital. Computers know how to count and keep time. [Eric Explains] has a video purporting to explain “every type of analog-to-digital converter.” We aren’t sure he got every possible method, but there’s still a lot of information in the video, which you can see below.

From the flash ADC, using a ton of comparators to the successive approximation converter, which essentially plays a game of hi/lo, guessing the answer and figuring out if the real answer is higher or lower.

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Does Your Terminal Speak Morse? This One Does

June 2, 2026 by Tyler August 7 Comments

There are a lot of single board computers on the market these days, so you can be forgiven if you missed the LuckFox Lyra. Its main claim to fame seems to be that it shares the Pi Pico’s 51 mm x 21 mm footprint while being powerful enough to run a full Linux system– or at least, it was. Now its claim to fame is as a device you can interact with no peripherals, accessing the terminal via Morse code. That’s thanks to [Gabriel Broussard Korr] and his Morstdin project, which should run on just about anything POSIX-compliant, by dint of a being a clever sh script at heart.

Of course, with most POSIX-compliant systems, you’ll need to alter the script to account for some kind of periferal to do the Morse I/O– not so on the LuckFox Lyra, which has a built-in LED and a single usable button. It actually has two buttons, but one of them is RESET and you can’t use that for anything but its intended purpose. The BOOT button, on the other hand, becomes user input after the system has started. One button, one LED? It’s almost like LuckFox designed this SBC for Morse! Admittedly we’d prefer an audible output, but adding a buzzer would detract from the purity of this implementation.

He’s had to extend the code, of course, since Samuel Morse did not expect all of the special characters you’re likely to encounter on the terminal. The resultant Programmer’s Morse, or PMorse is a straightforward extension, but [Gabriel] didn’t stop there: he’s also added a set of commands he describes as “vim-like” make using this headless device easier by doing things like deleting whole words or flash the line you’re working on so you can make sure you haven’t made any errors.

If that wasn’t enough, he’s also put an LLM on it. Because in the Year of Our Lord 2026, you apparently cannot escape the frakkin’ toasters by jumping your rag-tag fleet into the 128 MB of RAM on this tiny SBC. Still, his inclusion of Llamma.cpp does add one thing to the project: it can now claim to be the world’s smallest stand-alone chatbot. It’s also the only one that speaks Morse. That’s got to be worth some bragging rights.

[Gabriel] may have a thing for physically tiny Linux devices– his last project, which we featured, was about using Linux on old smartphones with Termux.

Thanks to [Gabriel] for the tip!

Header image credit Luckfox.

A Camera Viewfinder Makes A Great TV

May 31, 2026 by Jenny List 2 Comments

When we think of CRT camera viewfinders, most of us probably imagine the tiny CRTs you’d find in a 1980s camcorder. They’re super cute and a load of fun to play with, but they’re very much a consumer device. Professional cameras of the type you’d find in a studio had their own viewfinders, which were a lot closer to a small TV. They’re about as high quality as it gets for a monochrome CRT, and [Evan Monsma] has done the conversion to a general-purpose monitor.

On one side, this is a very straightforward hack, simply a case of tracing wires to identify the power and video pins. Given a tool battery, the monitor fires up and gives a super-sharp picture. What we like about this is the wooden base he’s made for the thing, at the same time rough-and-ready, and professional-looking from the outside. It has a routed space for the cables, and once mounted flush with the monitor base and given a bit of wood stain, it looks almost as though it was manufactured that way.

It’s likely most of us won’t find a broadcast viewfinder in the trash, instead settling at best for a little Chinese portable TV. But it’s still interesting to see these unusual devices. Perhaps it might make a good cyberdeck.

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21st Century Punch Cards Are 3D Printed And Read By OpenCV

May 16, 2026 by Tyler August 14 Comments

While a punch card is perhaps the lowest-density storage medium available, it has some distinct advantages. As [Bitroller] points out in the write-up of his punch card project, if he was using stainless steel instead of PLA his 3D printed punch cards would likely outlast everything he owns, and survive a five-alarm fire to boot. If you have 16 bytes you really, really don’t want to forget — or are willing to store your private key in a shoe box — this project might be of interest.

The nice part is that he’s built a handy Python script to generate printable files for the punch cards, which encode 16 bytes of information and 4 bytes of error correction using the Reed-Solomon algorithm. That’s just enough for a password and the error correction means up to two bytes can be recovered in the case of read failure.

The reading is where this gets interesting — again, [Bitroller] provides a handy script, but this one uses OpenCV to read the entire punch card at once from a webcam image, using the contrast between a black table and the light-colored PLA cards. It’s massively overkill and would have needed a supercomputer in the days when punch cards were common I/O, but that’s what makes this a great hack.

We only have one quibble: if you use additive manufacturing, can you still call it a punch card? Nothing was punched out, after all.

If you think punch cards are totally irrelevant in the modern day, well, you might be right– but that doesn’t stop us from playing with them. If punch cards make you think of Big Iron in the early days of computing, maybe think further back– they were used for everything from Jacquard looms to the original MIDI.

Measure The Earth’s Rotation Victorian Style

May 13, 2026 by Al Williams 8 Comments

You’ve probably seen a Foucault pendulum in a museum. This Victorian-era science demonstration is named after physicist Léon Foucault and shows how the Earth rotates compared to a pendulum moving in a fixed plane. [RyanCreates] shows you how you can make your own, and it is surprisingly simple.

All you need is a heavy weight like a small mushroom anchor, fishing line, and a swivel — all things you can pick up at any sporting goods store. You’ll need a way to suspend it all, such as an eye hook in the ceiling.

In addition to the mechanical parts, the build calls for a camera to record the results and a lighter or other source of flame. The reason? To release the pendulum, you burn a thread that prevents it from swinging. This allows for a clean release with no sideways force.

The amount of your rotation depends on your latitude. At 33 degrees north, for example, you can expect 360*sin(33)/24 or 8.17 degrees per hour of rotation. [Ryan] measured a somewhat larger number, which was probably due to an error source, especially since he is measuring the angle using captured camera frames in Photoshop. That has to introduce some error, and small pendulums like this are incredibly sensitive to errors.

If you try it and find the source of the error, we’re sure [Ryan] would love to hear from you. Museum pieces are typically much larger, have ultra-low-friction pivots, and use electromagnets to keep the pendulum moving since, after all, even a Foucault pendulum can’t run forever.

This Random Number Generator Does It With Neon

May 12, 2026 by Donald Papp 16 Comments

The quest for true randomness has roots in cryptography and is a rabbit hole that gets surprisingly deep with alarmingly rapidity. Still, the generation of random-enough numbers is a popular hacker project. Part of the appeal is the way these devices strive to incorporate physical phenomena, and in [Joshua Coleman]’s case, his Neon Entropy (Pseudo) Random Number Generator uses a trio of vintage neon lamps.

Neon lamps discharge at rates that vary unpredictably. They’re also pretty to look at.

[Joshua] chose neon lamps in part because the discharge rate of an energized lamp is a variable, physical process that makes a good source of entropy. They also have an attractive visual appeal that fits the concept [Joshua] had in mind. Unlike random number generators that kick off by measuring radiation or some other imperceptible thing, it’s possible — at least in a sense — to see this one working.

The small variations in the three neon lamps are measured optically by three TEPT4400 ambient light sensors (isolated from the neon lamps themselves) and turned into analog signals. A Raspberry Pi Pico W reads these signals, then uses them in a process that culminates in SHA-256 64-bit values that can be used as random seeds.

There’s also a web dashboard that shows everything live, furthering the “watch it work” concept [Joshua] is aiming for. The video below shows the project in action if you want to see how the sausage gets made.

Earlier we mentioned how random number generators are popular projects among hackers, and here are a few selected ones. Don’t miss the stylish glow and slick enclosure of this Nixie tube RNG, or the lava lamp RNG which is in fact not a gimmick. And while it is commonly understood that meaningful randomness must come from outside a digital chip, uninitialized internal volatile RAM — if accessed correctly — can be a remarkably good source of entropy.

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Wigglegrams With A Pinhole Camera

May 7, 2026 by Jenny List 10 Comments

A pinhole camera is almost a rite of passage in photography, given that you can make one so easily with little more than a cardboard box and enough tape to keep the light from coming through the cracks. [Socialmocracy] has made one that’s 3D printed, and it’s a nice design that takes 4″ by 5″ photographic paper. The shutter is held on with magnets, and the lid is attached with thumbscrews.

As neat as printed pinhole cameras are, it’s not as though they’re particularly uncommon. What makes this one stand out from the rest is that it’s actually two cameras in one. One box, two cameras, side by side. Landscape format and it’s a pair of panoramic cameras, while in portrait mode it’s a stereo camera. Even the simplest of cameras can do wigglegrams!

We like this camera, because it manages to add something to such a simple formula.. He’s taking comments on whether to release the STLs, so drop in your two cents.

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